In the manufacturing of integrated circuits and other semiconductor devices, the circuits and devices must be tested in order to ensure that a functional device has been manufactured. These tests are usually performed by contacting a test probe card to the relevant areas of the semiconductor device, sending current to the semiconductor device and performing one or more functional tests. Two main types of probe cards are currently used to make these connections.
The first main type of probe card uses a series of cantilever connectors that radiate inward from the edges of the probe card. When the probe card is lowered onto the semiconductor device to be tested, the cantilevered connectors connect to corresponding contact pads on the semiconductor device to complete the electrical connections for the test. Unfortunately, this type of probe card is limited due to the fact that the contact pads are limited to the peripheral of the semiconductor device to be tested, and cannot reach contact pads located in the central areas of the devices.
The second type of probe card uses an array of electrical connections in order to connect to a semiconductor device in other areas than the periphery. In this type of probe card, the electrical connections are spaced closely together in an array and are shaped so that the electrical connections absorb some of the shock of the impact when the probe card is lowered onto the semiconductor device to be tested. However, the minimum pitch (the distance between the electrical connections) for this type of card has historically been limited by the structure and shape of the electrical connections between the printed circuit board and the tips of the probe pins. Historically, the finest pitch attainable with this type of probe card is about 175 μm.
Unfortunately, as the dimensions of semiconductor devices are reduced in the ever-present drive for smaller and smaller devices, the pitches of these types of probe cards will be unable to adequately test semiconductor devices requiring a smaller probe pitch. Accordingly, a probe card with a smaller probe pitch is needed.